Aurion and LPG petrol performance

[Gregau]

I'm considering an Aurion to be my next 10 year car (yeah I keep cars that long) and with the price of fuel to be unimaginable in that timeframe I'm looking at converting to dual fuel with the conversion kits now available for them.

I've read a couple of threads on here and the general consensus is to stay away from LPG...thats fine but I'm planning on keeping the car for the long haul so that makes LPG a definite option.

I've calculated roughly that I would break even after about 2 years...maybe a little less.

One thing I'm trying to find out is...does the cars performace on PETROL suffer after conversion to dual fuel?

In other words...does the tuning required to run the car on gas lower the performance when the car is running on petrol mode?

Has anyone here converted an Aurion to LPG and happy with the results? I'm guessing it's far too early for anyone to comment on reliability so how about performance? I'd be wary if I'm going to lose any performance when running the car on petrol because of whatever tuning etc.

Also...This seems to be a primarily Aussie forum. Does anyone know whats going on with the LPG rebate right now?

Is it scrapped altogether or the amount halved? Can on estill get the full 2 grand and if so is there a grace period etc to when it is scrapped or lowered?

Finally...if I was to leave it on petrol...what are people getting roughly on a tank of city driving? 550kms? 600 kms?

My crapola Falcon currenty gets me a painful 420 kms per tank....eurgh.

Cheers all.

[dannywss]

I remember quoting for getting LPG conversion and asked about power/performance loss, they replied that i would be looking at 10% loss and more lag during acceleration.

The lag from acceleration also can be seen in other LPG cars, especially taxi?

[Gregau]

Thanks but is that for running on petrol or LPG or both?

[dannywss]

both.

[ZZR88]

I fill up with 98 Vortex and get around 580KM out of a full tank

[Gregau]

Okay I've done some reading and apparently there should be NO LOSS of power when running on petrol in a duel fuel system as the electronics of new systems just switch ignition curves between the two.

[dannywss]

Seeing your reply, i went to google for more answers.. as i had my answer for a qualified LPG conversion shop a year ago.

There are results that saying 10% loss of perfromance:

http://www2.abc.net.au/science/k2/stn/sept...opic135013.shtm

But there are more result saying this "Negligible loss in performance, so small you won’t notice it.."

http://www.cfreelpg.co.uk/questions.htm#q4 saying "The loss of performance is normally 5% of bhp on LPG"

If you do your reading yourself, do it, rather asking here, coz i dont believe someone in this section will do LPG conversion to such new car and void your warranty.. better, start going different shops to ask about the performance loss..

Good luck..

[dave262]

When you are saying that you will break even in 2 or so years, also consider that there is an increase in maintenance costs with ANY LP-Gas car.

This is due to the fact that gas does not have as much natural lubrication as there is in fuel, which therefore creates significant increase in wear and tear - particularly on the valve seats. There is also a difference in octane rating, and you will find that a direct comparison of the same volume of either fuel - petrol will actually have better economy.

Another thing to consider is the type of technology used for the conversion, as there is the option of mixer-style (gas is mixed with air in the intake), or direct injection. Direct injection systems have significant advantages over standard mixer-style arrangements, including improved performance and reliability. They are however very expensive, and will usually require some form of custom ECU to be installed alongside the standard ECU. I am not sure whether it is even possible to run these setups in a dual-setup with fuel either, as I cannot see how the same injector could run both fuels (I could be wrong here though).

The mixer-style is an old style of gas injection that is used in almost all existing (older) setups, and requires regular tuning to prevent air intake backfires (basically gas igniting back through the intake - very nasty!), and will require parts to be replaced every couple of years; as there are rubber diaphragms involved within the setup which deteriorate. If you skip out on these services, you risk significant damage to the intake and air metering systems. You will find in these systems also, you must start the car running from fuel as the gas will simply condensate on the cold fittings and will not vaporise until the engine is warm. The only advantage of these systems is they are cheap.

With both forms of gas to help prevent valve wear, you will likely have to use some form of additive in the oil too. You will also void warranty if you do the conversion, as the engine components are not designed to be compatible with gas in the Aurion and it is not a factory-offered conversion. You must also ensure the gas tank is checked at regular intervals for leaks or damage.

Personally, I would not go near gas with an Aurion, and as I am sure I have seen elsewhere in a post somewhere on this forum - there are numerous reasons why it is simply unnecessary. I drive around in the city all the time, and out in the inner suburbs, and I find I average about 11.5L/100km, which is very reasonable. I only fill up the car once every two weeks and the cost is not too bad, as there is usually enough fuel still in the tank anyway. I drive long distance on freeways sometimes too, and have found the economy to get around 6L/100km if I am careful. With these sort of ratings, compared to the cost of installing and maintaining a gas setup - the benefits of petrol quickly become obvious.

Edited May 20, 2008 by dave262

[dannywss]

What dave262 said was what i heard from a LPG conversion shop 3 years ago, which is very correct and reminded me of everything.. He is not just talking for Aurion, but basically for all cars in the market.. These are the reason too why we havent found a car designed and advertised to run on LPG..

Petrol/Diesel is still the way to go for.. i dont know how long, maybe not when petrol cost doubles up again in very near future..(very very near future, if you watch CNN everyday, petrol price goes up every few minutes)

[Gregau]

The new Aurion system is a direct injection system and the cost is $4400 !!!

So that's at least $2400 out of pocket if the subsidy stays the same, and the amount of kms I do every year it would take me about 3 - 3.5 years to break even...and I didnt even factor in the extra service costs of the system...lemme guess 150 - 200 every 20,000 or so at least, no way this is looking even close to worth it for me personally.

I was kindof aware from experience of the extra wear on valve seats and higher running temps etc, but was prepared to ignore it (aka put in the back of my mind) but it still is a factor. You read all the propaganda from the LPG places saying it's better for your motor as it doesnt wash oil from cylinder walls etc etc...but they dont mention anything about the valves seats do they hehe.

Nah my mind is made up...if it paid for itself in 6 months then I'd seriously consider it but I may not even have the car for as long as it's gonna take to break even (planning on keeping it for about 10 years but you never know).

Edited May 20, 2008 by Gregau

[Danos]

I believe that the cost of LPG has been low as the fuel excise tax on LPG (or something like that) by the government has been kept low. However there has always been talk of a fuel excise tax reform which may lead to LPG price lift sometime . . I'm sure I read an article or saw something on TV at some time over the last year.